# Select API Quickstart Guide [![Slack](https://slack.min.io/slack?type=svg)](https://slack.min.io)

Traditional retrieval of objects is always as whole entities, i.e GetObject for a 5 GiB object, will always return 5 GiB of data. S3 Select API allows us to retrieve a subset of data by using simple SQL expressions. By using Select API to retrieve only the data needed by the application, drastic performance improvements can be achieved.

        return int(sip.Sum64() % uint64(cardinality))
}
```

Input for the key is the object name specified in `PutObject()`, returns a unique index. This index is one of the erasure sets where the object will reside. This function is a consistent hash for a given object name i.e for a given object name the index returned is always the same.

Create a bucket named `functionbucket`
```
mc alias set myminio/ http://localhost:9000 minioadmin minioadmin
mc mb myminio/functionbucket
```

Create a file `testobject` with some test data that will be transformed
```
cat > testobject << EOF

configuration using e.g. the `mc admin config` commands you will need to adjust
your deployment.

Even though this change is backward compatible we do not expect that it affects
the vast majority of deployments in any negative way.

> Will an upgrade of an existing MinIO cluster impact the SLA of the cluster or will it even cause downtime?

2018/12/26 17:49:36 listening on http://localhost:8888/
```

This will open the login page of keycloak, upon successful login, STS credentials along with any buckets discovered using the credentials will be printed on the screen, for example:

```
{
  "buckets": [
    "bucket-x"
  ],
  "credentials": {
    "AccessKeyID": "6N2BALX7ELO827DXS3GK",

    {
      "Effect": "Allow",
      "Action": [
        "s3:*"
      ],
      "Resource": [
        "arn:aws:s3:::*"
      ]
    }
  ]
}
```

### Visit <http://localhost:8080>

You will be redirected to dex login screen - click "Login with email", enter username password
> username: ******@****.***
> password: password

and then click "Grant access"